Carb Issue

[Kyle1515]

I have a 750 KB carb on an IMCA spec engine. When i go to roll into the throttle it stubbles until past 1/4 throttle. It idles fines and when you rev it in the pits with no load on it there isnt an issue. I notice it even when pulling out on the track in low gear until i get it above 1/4 throttle. Any ideas?

[hucktyson]

Honestly call Karsten at KB. He has the best tech support in the industry bar none. He always answers and he will fix your problem

[save the racers]

Are the squirters functioning correctly? Strong stream when you pump them? Ive just had idling issues and problems with the squirters clogging up on mine. While it is a great carb i called KB one time and will not call back unless i need to send it back or get parts.

[lazermod3]

I have a 750 KB carb on an IMCA spec engine. When i go to roll into the throttle it stubbles until past 1/4 throttle. It idles fines and when you rev it in the pits with no load on it there isnt an issue. I notice it even when pulling out on the track in low gear until i get it above 1/4 throttle. Any ideas?

Cam lever to pump adjustment! If it isn't correct it will stumble.

[HuckleberryB4]

Yep, Karsten is local and I can't stand to talk to the guy. Arrogance at it's finest. Unless you're one of his buddies or a big dog. We'll be sending ours out from now on.

BTW Kyle, my carb does the same thing. Called Karsten and his exact words were "What do you want me to do, fix it over the phone." All I wanted was a suggestion or two, A$$clown.

[moose52]

Im leaning towards lazermod3. Sounds like cam lever/spring adjustment. If you have a high idle you tend to use up a lot of the cam rotation, so when you hit the loud peddle there's not as much to cover the WOT. At idle make sure you have a little clearance between the bolt/spring and the lever that goes to the diaphram. Is it a 30 or 50cc pump? You can also tailor the 'length of time' of the pump shot via the shooter nozzle size. Smaller provides more restriction, so a longer shot. Also is a single pump or double and is it progressive on secondary or 1:1. If its single pump the later information means nothing. But double pump it might.

[hucktyson]

Karsten is not arrogant he's incredulous and there's a huge difference . When someone calls him he has no idea what the caller does or doesn't know so he asks all of the details from the beginning which makes some people feel that he's talking down to them. He has to assume you know nothing so he doesn't accidentally miss your problem. If you want the problem fixed let him answer your questions without talking over him and don't get offended when he asks you questions you think are beneath you . Imagine being at your job and have a guy who may or may not be a
Customer call and ask stupid questions and then interrupt you when you try to answer.

[12 Mod]

I was wondering if you got this resolved and what the problem was. I have a carb doing something similar.

[racer15]

If you want to talk to a nice guy with gret tech support call john at JDR i have bought 2 carbs from him for two different engines and they run great!

JDR Performance, LLC
Marshfield, MO 65706
417-859-2353
info@jdrperformance.com
Monday-Saturday
8:00am - 6:00pm

[W2racing]

I have a 750 KB carb on an IMCA spec engine. When i go to roll into the throttle it stubbles until past 1/4 throttle. It idles fines and when you rev it in the pits with no load on it there isnt an issue. I notice it even when pulling out on the track in low gear until i get it above 1/4 throttle. Any ideas?

Try smaller acc. pump nozzles. Too big of nozzles/too much fuel too soon will cause a low end stumble. Ex. if u have a 36 nozzle drop down to a 32 nozzle.

[stock car driver]

When Ive had that happen it was from too small of a disch nozzle on a two barrel from willys, they were making their own and they were tiny so they had in the pits snap to them...